Hey thanks for the reply!
My initial approach has been using an emissive material. Problem is I need to hide the object in the camera view. It’s a very niche edge case.
In the short clip below (hopefully uploads correctly, I’m a newbie here). The entire top of the keyboard is rendered in Unreal and sent to OBS over spout. The image behind me is also rendered in UE, but is being shown with a projector. To fake the reflection and light of the projector I used a plane with an emissive material and a Render Target.
Using UE 5.3 (now Deprecated) Raytracing Reflections I was able to hide the object but still capture the emissive material and object in the camera. I’m attempting to update to 5.5 and thought using Rect Light with Source Texture as a Render Target would be a good alternative, but I need the light to be dynamic as the scene behind me changes a lot.
I’m going to try and use the Nvidia RTX branch to see if I can achieve the result in a different way. Failing that I guess I’ll stick with 5.3 until I find another solution.